灭多威在水稻上的残留检测及降解动态研究

利用气相色谱-火焰光度法(GC-FPD)研究了灭多威在水稻田田水、土壤、水稻植株和水稻糙米中的残留及降解动态. 当灭多威的添加量为0.045～0.450 mg/kg时，其在水稻糙米、植株、土壤和田水中的平均回收率分别为82.8%～91.0%，84.4%～98.1%，83.7%～90.3%和85.9%～86.9%，变异系数分别为5.2%～8.1%，6.8%～9.0%，3.7%～7.7%和6.4%～8.3%. 测定了灭多威在湖南长沙、湖北罗田、江西樟树和浙江杭州4个水稻主产区的水稻植株、土壤及田水中的降解动态. 结果表明，灭多威在湖南长沙、湖北罗田、江西樟树和浙江杭州的水稻植株上的降解半衰期分别为16.08，4.47，15.93和22.87 h，在湖南长沙、湖北罗田和江西樟树水稻田田水中的降解半衰期分别为6.74，3.88和28.06 h. 灭多威在浙江杭州水稻田田水中未被检出，其在4个研究区稻田土壤中也未被检出. 按照推荐剂量的倍量施药，在施药14 d后，灭多威在水稻糙米中的残留量均低于日本肯定列表制度规定的在稻米上的最大残留允许量(0.5 mg/kg). 

Residue Detection and Degradation Dynamics of Methomyl in Rice

The residue and degradation of methomyl in brown rice,rice plants,soil and water of paddy fields were investigated using a gas chromatography-flame photometric detector(GC-FPD) method.As methomyl was applied at a range of concentrations from 0.045 to 0.450(mg/kg),average recoveries of 82.8%-91.0%,84.4%-98.1%,83.7%-90.3%,and 85.9%-86.9% were obtained in the brown rice,rice plants,soil and water samples with variations of 5.2%8.1%,6.8%-9.0%,3.7%-7.7%,and 6.4%-8.3%,respectively.The degradation dynamics of meth...